Skiving-machine.



-PATENTED .TUNE 16,' 1908. D. VN. ROBERTSON. I l SKIVING MACHINE. APPLIGATION l121mm APB. 24, 190s.

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No. 890,928. PATENTED JUNE 16, 1908. D N ROBERTSON SKIVING MACHINE. .APPLICATION FILED APB. 24. 1905.

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No. 890,928. PATENTED JUNE 16, 1908.

D. N. ROBERTSON. 9

SKIVINGMACHINE. APPLIOATIGN FILED APR. 24, 1905.

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in? 'I y wwwa... fb/L/ DAVID N. ROBERTSON, OF LYNN, MASSACHUSETTS.

SKIVIN G-MACHINE Specification of Letters Patent.

Patented June 16, 1908.

Application led April 24, 1905. Serial No. 257,078.

To all whomt may concern:

Be itknown that I, DAVID N. ROBERTSON, citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented a certain new and useful Improvement in Skiving-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object to provide an improvement in leather skiving machines of the kind employed in skiving blanks for box toe caps, boot and shoe counters, and the like.

It is particularly an improvement upon the machine shown in my Letters Patent of the United States, No. 838,903, granted to me December 18, 1906, upon application filed January 13, 1904, Serial No. 188,821.

My present machine is of the same general type as the machine there shown, and the improvements which I have made thereon relate especially to the adjustment of the socalled pressing fingers; and the means employed for giving the pressing fingers the requisite pressure upon the blanks as they pass between the feed wheels and the matrix.

The invention will be fully understood from the following description taken in cone nection with the accompanying drawings, and the novel features thereof Ywill be pointed out and clearly defined in the claims at the close of this specification.

In the drawings, Figure 1 is a plan view, and Fig. 2 a side elevation of the machine embodying my invention. Fig. 3 is a section on line 3, 3, Fig. 2, looking in the direction of the arrows on the said line. Fig. 4 is a detail of the adjustable supporting means for the ends of the pressing fingers.

Referringl to the drawings, at A is indicated a table, suitably supported upon the frame A of the machine and the base A2. Upon the table A, reciprocates the carrier B which is provided with a feed plate C by means of which the blank is carried forward to the skiving mechanism. This skiving mechanism consists of a matrix D, feed wheels E and skiving knife F, the same being situated in the usual relations to each other. During their passage between the matrix D and the feed wheels E, the blanks are forced into de pressions in the matrix D by means of the usual pressing fingers Gr pivoted at H in the well-known manner.

The machine is driven by a belt upon the pulley I through the gears J and K. The

larger of the two gears K is located upon the feed wheel shaft L, fast to which is located the pinion M. The matrix shaft N is driven by a second pinion O fast thereon which meshes with the pinionM. The pinions M and O are of the same size and therefore the matrix D and feed wheels E are given the same peripheral speed. The feeding mechanism, t'. e., the carrier B and feed plate C are opere ated from the feed wheel shaft L by means of the crank P fast thereon, and the pitman rod Q. The feed wheels E are supported upon a floating yoke E in the well-known manner. The machine as thus far described, is substantially like the machine of my above mentioned application. y

In order that the center of the blank may be presented to the proper point of the matrix, to get an adjustment by means of which the proper thickness may be given the edges of the finished work, I provide the following arrangement of guides and adjusting mechanism for the said matrix. At 1 is shown a side guide against which the substantially straight sides of the pile of blanks to be skived are placed by the workman. This side guide consists of a vertical plate of iron or other suitable material fixed to the frame of the machine.

I-Ieretofore it has been common in machines of this character to move the guides and blank carrier with relation to the matrix v to center properly the blank as it passes for- Ward to the skiving mechanism. InV my present machine I make the guides and feed. plate substantially fixed and ythe matrix movable longitudinally of its shaft thereby obtaining the required adjustment by movement of the matrix instead of by corresponding movements of the guides and blank carrier. `This arrangement. has certain obvious advantages, especially that of having fewer movable parts. It also places the adjust ment under the control of a single thumb nut, which ma be moved by the operator while the mac ine is in motion, thus enabling him to adjust the machine slightly, as blanks are being skived, to obtain exactly the desired results.

In practice, I provide the side guide 1 with lugs 2 and 3, by means of which the said side guide may be conveniently secured by the cap screw 5, to the vertical rib 11 of the frame of the machine, so that the said side guide is substantially fixed, and thus becomes a part of the frame of the machine.

At 6 is shown the usual front gage or gate, which is vertically adjustable, to permit a single blank to pass forward at a time to the skiving mechanism. This adjustment being well known, I have not shown the means by which it is obtained.

vThe lateral movement of the matrix D with relation to the path of movement of the reciprocating feed plate C is produced in the following manner. rIhe matrix shaft N is supported in suitable bearings 7 in the frame of the machine, and is provided with a collar 8 fast to the said shaft. The said shaft N is free to move longitudinally in its bearings. Upon the back of the frame of the machine, I place the lugs 9, 10 and 11, for the support and guidance of the adjusting rod 12 which terminates at one end in a fork 13 engaging the said collar 8 and at the other end is screw-threaded as shown at 14, and has placed thereon a thumb nut 15, furnished with a sleeve 16 and collars 17 and 18, which engage the lug 9. By turning the thumb nut 15, the adjusting rod 12 is moved forward or back as the case may be, and the matrix shaft N and matrix D are given corresponding movement. The adjustment may be made when the machine is in motion and does not interfere with the driving of the matrix shaft, because the two gears M and O are made of sufficient width to permit slight lateral movement.

I will now describe my improved method of giving the pressing fingers G the requisite pressure.

Referring now to Figs. 2 and 3, the pressing fingers are shown as resting upon an adjusting device to be later described. Across the back ends of the pressing lingers G, I place a yielding abutment 20, and between it and the ends of the pressing ngers a block of rubber 19, which is inclosed in a suitable casing 201., formed as a part of the said yielding abutment 20.' Said block of rubber' 19 is composed preferably of a single piece of ordinary soft rubber and when used in this connection has certain advantages which I have pointed out in my previous application heretofore referred to. The said yielding abutment 20, is provided with an arm 21 extend ing toward the right hand or front of the machine, pivoted at 22 to the fulcrum arm 23 which extends upwardly from the base A2 of the machine. The yielding abutment 20, and the arm 21 are held down forcibly upon the block of rubber 19 and pressing fingers G, by means of a spiral spring 24 attached at its lower end to the base A2 and at its upper end to a spring spindle 25 which passes through a hole in the arm 21. The upper end of the said spring spindle is provided with screwthreads which engage a thumb nut 26 and enable adjustment of the tension of the spring to be readily made. I find that this combination of the rubber block 19, and the adjustable yielding abutment 20, enables me to produce a better grade of work than has heretofore been possible. `Where the rubber block and an unyielding abutment is used I have found that if :for any reason the blank passing through the machine is one of unusual thickness, the pressing lingers G are liable to be permanently sprung by reason of the fact that the rubber block 19 becomes substantially incompressible after a certain point of compression has been reached. My present arrangement provides means which permits the abutment to yield when the point of compression at which injury to the lingers is likely to take place has been reached. I am also enabled by this means to adjust the pressure applied to the fingers by a single movement of the thumb nut 26.

I provide the following adjustment to take up the wear of the ends of the pressing iingers G wherel they bear against the blank as it passes between the feed wheels and the matrix. This wear takes place very rapidly and unevenly owing to the character of the matrix against which the ends of the fingers bear. It is, therefore, desirable that means be provided for rapid and easy adjustment of the fingers individually as well as an adjustment for all of the fingers at one time. To accomplish this, I place beneath the front end of the fingers G a slotted block 27 which is movable vertically on the rib 28 which is formed upon the frame A of the machine, the said slotted block 27 being provided with a corresponding groove or way for the reception of the rib or guide 28. The slotted block 27 is adjustable vertically by means of the adjusting bolt 29, which is provided with a convenient head 30 and pair of collars 32 which engage the slotted lug 33 on the frame of the machine. The lower end of the said adjusting bolt 29 is screw-threaded to engage a corresponding tapped hole in the said slotted block 27, being held against the rib 28 on the frame of the machine by means of a bolt 34 movable in the corresponding slot 35.

The said slotted block 27 is provided with a series of vertical slots 36 for the reception of the ends of the said pressing ngers G, and said slots 36 are slightly wider than the said pressing fingers, in order that the fingers may have free play therein. In practice, I make three or four of the slots deeper than the others, as shown at 37, in order that the walls notches 40, and the said cams or eccentrics project beyond the front or right hand wall of the slotted block 27, so that the operator may get at the said notches l0 With any convenient tool as a screw driver, and move the cams slightly by prying over the edge of the block 27.

I/Vhen it is desired to adjust the canrs individually, the nut 381 is loosened, thereby loosening the said cams 39 in the slots 36. The operator then moves the cams under the various lingers G which require adjustment. It is to be noted that the cams lit their respective slots so closely, that even when the nut 38 is loosened, they can be moved only with the aid ol some convenient pry tool. Alter the adjustment has taken place, the nut 38 is tightened, so that the cams are held immovably beneath the pressing lingers. This adjustment ol the pressing lingers, enables me to produce much better' results in my machine without the necessity of frequently grinding the ends of the pressing lingers, which has heretofore been necessary, and my machine as a whole produces excellently skived work by reason ol the improvements which I have described herein.

I/Vhat I claim is:

l. In a machine of the character described, the combination oi pivoted pressing lingers, a yielding abutment, and an elastic cushion intermediate the said yielding abutment and the ends of the said pressing lingers.

2. In a machine of the character described, the combination with pivoted pressing lingers ol a rubber block therefor, and a spring Operated abutment, the said rubber block and abutment operating to maintain the lingers in operative relation with the work.

3. In a machine ol the character' described, the combination with pivoted pressing ngers of a rubber block, an abutment lor the said rubber block, a pivoted arm last thereto, and a spring connected therewith, and tending to hold said abutment and rubber block u pon the ends ol the pressing lingers.

4. In a machine ol the character described,

the combination oi pivoted pressing lingers, a yielding abutment, coperating with the said lingers on one side, and adjustable supports coperating with the said lingers on the opposite side and comprising a cam or eccentric.

5. In a machine ol the character described, the combination ol pivoted pressing lingers, a yielding abutment on one side of the ends ol the said pressing fingers, a Islotted block on the other side receiving the ends ofthe said pressing lingers within slots therein, and adjustable supporting means lor the said pressing lingers comprising a series ol cams or eccentrics one for each pressing linger, and. located Within the slots in the said block.

6. In a machine ol the character described, the combination of pivoted pressing lingers, a yielding abutment, above the said pressing lingers, and individually adjustable supporting means lor the ends ol the said pressing lingers.

7. In a machine of the character described, the combination ol pivoted pressing lingers, a yielding abutment above the said pressing lingers, a block provided with slots for the reception ol the ends of the said pressing lingers, and adjustable supporting means for the ends of the said pressing lingers within the slots in said block.

S. In a machine of the character described, the combination of pivoted pressing lingers, a yielding abutment above the said pressing lingers, a block provided with slots for the reception ol the ends of the said pressing lingers, and adjustable supporting means lor the ends of the said pressing lingers comprising cams or eccentrics in the said slots.

In testimony whereof I aliix my signature, in presence of two witnesses.

DAVID N. ROBERTSON. 

